The development of endoscopes able to visualize the stomach of horses showed that the frequency of gastric ulcers in horses is higher than presumed. The aetiology of gastric ulcers in horses is not well known but it is assumed that stress plays an important role in some cases.
It is well-known to treat gastric ulcer in horses and foals by the administration of a proton pump inhibitor which is preferably 5-metoxy-2-[[(4-metoxy-3,5-dimethyl-2-pyridinyl)methyl]sulphinyl]-1H-benzimidazole, whose common name is Omeprazole. A paste for horses containing 37% w/w. Omeprazole is marketed under the trade name Gatrogard for the treatment of ulcers. Generally, this paste is to be administered orally once a day for 4 weeks at the dosage of 1.8 mg omeprazole/lb body weight (4 mg/kg). Thereafter, recurrence of gastric ulcers can be prevented if the treatment is continued for at least an additional 4 weeks at a lower dose of 0.9 mg/lb (2 mg/kg).
Proton pump inhibitors (PPI) are potent inhibitors of gastric acid secretion by inhibiting H+K+−ATPase, the enzyme involved in the final step of hydrogen ion production in the parietal cells.
The PPI omeprazole is disclosed in U.S. Pat. No. 4,255,432.
Pharmaceutical compositions containing proton, pump inhibitors are also disclosed in the PCT Patent Application WO 96/31213 and U.S. Pat. No. 5,708,017 which discloses a stable, ready-to-use oral paste composition of proton pump inhibitor, such as, for example, omeprazole.
Another oral composition containing proton pump inhibitor is known from WO 94/25070 in the form of enteric coated dry particles mixed with a dry gelling agent.
For a good review of the diagnostic and treatment of equine gastric ulcer syndrome (EGUS) or gastrointestinal ulcers, see EQUINE VETERINARY EDUCATION (1999) 11 (5) 262-272.
While treatment of ulcers and prevention of recurrence of the treated ulcers is known and is efficient, no method of prevention of ulcers, including gastric ulcers in animals, including horses and dogs where ulcers are relatively frequent, is known and it was believed that such prevention would be very difficult. Moreover, the far insufficient knowledge of the aetiology of the ulcers added to the difficulty of conceiving a method able to prevent occurrence of ulcers in animals.